[Antioxidant activity of the blood serum in pregnant and nonpregnant women: comparison of various detection methods].

Antioxidant activity (AOA) of the serum was assessed in pregnant and nonpregnant women by three different methods. AOA assessed by the chemiluminescent method with riboflavin was increased in pregnant women (30-39 weeks) in comparison with donors. This increase may be due to appearance of a specific protein component possessing a high AOA in the serum of pregnant women. Measurements of AOA by two spectrophotometric methods, with DPPH and quercetin, showed a decrease of AOA in pregnancy. Analysis of correlations shows that in donors all the methods used reflect the activities of virtually the same components of antioxidant defense, whereas in pregnant women the composition of the predominant antioxidant components is changed. Hence, application of several methods or measurement of certain components of the antioxidant system is advisable in pregnant women.